Prehospital Transcutaneous Cardiac Pacing in the United States: Treatment Epidemiology, Predictors of Treatment Failure, and Associated Outcomes.

Objectives: Transcutaneous cardiac pacing (TCP) is a potentially lifesaving therapy for patients who present in the prehospital setting with bradycardia that is causing hemodynamic compromise. Our objective was to examine the outcomes of patients who received prehospital TCP and identify predictors of TCP failure.

Methods: We utilized the 2018-2021 ESO Data Collaborative public use research datasets for this study. All patients without a documented TCP attempt were excluded. Mortality was derived from hospital disposition data. TCP failure was defined as the initiation of CPR following the first TCP attempt among patients who did not receive CPR prior to the first TCP attempt. Multivariable logistic regression models using age and sex as covariables were used to explore the association between prehospital vital signs and TCP failure.

Results: During the study period, 13,270 patients received transcutaneous pacing and 2560 of these patients had outcome data available. Overall, the mortality rate following TCP was 63.4%. Among patients who did not receive CPR prior to the first TCP attempt (n = 7930), TCP failure (progression to cardiac arrest) occurred 20.4% of the time. Factors associated with TCP failure included increased body weight (>100 vs. 60-100 kg, aOR: 1.33 (1.15, 1.55)), a pre-pacing non-bradycardic heart rate (>50 vs. <40 bpm, aOR: 2.87 (2.39, 3.44)), and pre-TCP hypoxia (<80% vs. >90% SpO₂, aOR: 6.01 (4.96, 7.29)).

Conclusions: Patients who undergo prehospital TCP are at high risk of mortality. Progression to cardiac arrest is common and associated with factors including increased weight, a non-bradycardic initial heart rate and pre-TCP hypoxia.